Expose fractional TouchEvent coordinates

Source/platform/scroll/ScrollView.cpp

Index: Source/platform/scroll/ScrollView.cpp
diff --git a/Source/platform/scroll/ScrollView.cpp b/Source/platform/scroll/ScrollView.cpp
index 3fae4b88bd6c0d395032038a997daa85c4081fa2..346f7e8a71bed6413d29af2ef1345d0d531d7bd6 100644
--- a/Source/platform/scroll/ScrollView.cpp
+++ b/Source/platform/scroll/ScrollView.cpp
@@ -601,6 +601,12 @@ IntPoint ScrollView::windowToContents(const IntPoint& windowPoint) const
     return viewPoint + scrollOffset();
 }
 
+FloatPoint ScrollView::windowToContents(const FloatPoint& windowPoint) const
+{
+    FloatPoint viewPoint = convertFromContainingWindow(windowPoint);
+    return viewPoint + scrollOffset();
+}
+
 IntPoint ScrollView::contentsToWindow(const IntPoint& contentsPoint) const
 {
     IntPoint viewPoint = contentsPoint - scrollOffset();